A Scientific Look at the Benefits of Probiotics
I’m concentrating on probiotics and fermenting for the month, and this is the first installment, here is an index I’ll add posts to as I publish them. I wanted to write an epic thorough post on probiotics, complete with scientific references and explanations. The problem is, that’s called a book. For now, please accept this truncated and incomplete version. I’ve tried to include ample sources to demonstrate that the immense importance of probiotics is not some hippy-feel-good theory, but grounded in science.
I’ve long known that ‘probiotics’ were good for you in a general way, hearing advice to take them after antibiotics. We are, however, discovering functions of probiotics that are actually fundamental to our well being, as opposed to being a nice thing to have. Studies and experiments are continually discovering new ways that these little bugs benefit the human host and I think we are just starting to uncover the tip of the iceberg.
Probiotics are mostly bacteria, with a few kinds of yeast, that populate our bodies. We tend to concentrate on the ones that reside in the gut, but beneficial bacteria are also present on all the places of contact with the ‘outside’ world, including skin, eyes, genitals, and breastmilk. For our purposes, we will focus on beneficial flora in the gut.
Technically, probiotics are defined as “live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host” by the World Health Organization. This definition is mostly in reference to supplements and advertising claims, so that ‘probiotic’ on a label must have scientific evidence of some health benefit from the strain of bacteria or yeast that is being promoted. With an estimated 1000 species of beneficial flora residing in or on the human person and however, there is much more research before all the health benefits that do exist are found out. And of those 1,000 species of beneficial bacteria in the human ‘eco-system’, each of those species has multiple strains, each of which can have a different influence on the human host.
As an example of how much we don’t yet know, the second most common bacterial species listed in the American Gut Project ( a project examining swabs/samples from a variety of people mostly in the United States) doesn’t have a name – in fact, it doesn’t even have a named genus. And the most common bacteria mapped by the American Gut Project is practically non-existent in the Hanza tribe of Tanzania, a group still living a hunter-gatherer lifestyle. This study, as well as other, indicates that the composition of an individual’s microbes is dependent on that individual’s diet.
